Tribological performance of SS 316L, commercially pure Titanium, and Ti6Al4V in different solutions for biomedical applications

The body fluid plays a vital role in the degradation of metallic bio-implant during motion. The present investigation evaluates the tribological behavior of austenitic stainless steel (SS 316L), commercially pure titanium (cPTi), and grade 5 titanium (Ti6Al4V) in different body fluids like artificial saliva (AS), phosphate buffer solution (PBS), ringer's solution (RS), and simulated body fluid (SBF). The chemical composition of all these solutions is nearly the same as human body fluid. The wear rate and coefficient of friction (cof) were evaluated for each sample in wet conditions against a zirconia ball of diameter 10 mm at a constant load of 10 N. The scanning electron microscopy (SEM) image of the worn surface is used for wear rate calculation. Ti6Al4V showed the lowest cof in the ringer solution and the highest in SBF. The average cof value against the counterpart of SS 316L, cPTi, and Ti6Al4V increases in SBF. All three samples showed more than 0.61 cof in artificial saliva. The cof value under PBS shows a moderate result for all the samples at constant load. This study reveals the application of these implant materials at a specific location according to the body fluid concentration.